The GCI-methodology, which was developed earlier through introduction of a five-level classification scale for twelve aggregated indicators of global competitiveness of the countries, is used for constructing the frequency tables of the number of cases of different global competitiveness levels, the matrices of global competitiveness levels of the countries on twelve aggregated GCI indicators and the matrices of the strengths and weaknesses of the global competitiveness for three groups of the countries of Sub-Saharan Africa. It is shown that Mauritius, Rwanda and the Seychelles Islands have the best positions in the global competitiveness. All these countries are close to reach the lower bound of the high global competitiveness level. The authors suggest two variants for calculating the aggregated indicator of global competitiveness of the arbitrary group of the countries that have led to the close results of the calculations for the three groups of countries in Sub-Saharan Africa. The calculations showed that the above mentioned aggregated indicators for COMESA countries exceeded those for countries of ECOWAS and ECCAS, and for the last two countries these indicators were almost the same.